[eluser]TheFuzzy0ne[/eluser]
sendmail is part of PHP, so that should still work. However, it's a bit strange that the Email library is causing the problem. I'd suggest making a copy of ./system/libraries/Email.php and putting it in ./system/application/libraries. Then you can edit ./system/application/libraries/Email.php, and add some debugging code to help you locate the problem.
EDIT: Sorry, I was referring to
mail not sendmail.
